Removal Procedure
- Remove the windshield garnish molding. Refer to Windshield Pillar Garnish Molding Replacement .
- Remove the upper trim pad. Refer to Instrument Panel Upper Trim Pad Replacement .
- Disconnect the red 32-way electrical connectors and the blue 32-way electrical connector.
- Disconnect the global position system (GPS) cables (1) from the VIU.
- Loosen the 4 bolts and release the hook tab by rotating the module upwards in order to remove the VIU from the bracket.
- The old VIU must be returned for core credit.
Important: The vehicle interface unit (VIU) has a specific set of unique numbers that tie the module to each vehicle. These numbers, the 10-digit station identification and the 11-digit electronic serial number, are used by the National Cellular Network and OnStar® to identify the specific vehicle. Because these numbers are tied to the vehicle identification number of the vehicle, you must never exchange these parts with those of another vehicle.
Important: Do NOT remove the VIU/VCU bolts from the bracket.
Installation Procedure
- Record the 10-digit STID number from the label on the VIU module.
- Install the VIU to the bracket by rotating the VIU downwards into the hook tab.
- Connect the GPS cables (1) to the VIU.
- Connect the red 32-way electrical connectors and the blue 32-way electrical connector.
- Install the bolt (2) which secures the VIU bracket to the instrument panel brace.
- Install the upper trim pad. Refer to Instrument Panel Upper Trim Pad Replacement .
- Install the windshield garnish molding. Refer to Windshield Pillar Garnish Molding Replacement .
- Reconfigure the OnStar® system. Refer to OnStar Reconfiguration .
Notice: Refer to Fastener Notice in the Preface section.
Tighten
Tighten the bolt to 10 N·m (89 lb in).
Important: After replacing the VIU, you must reconfigure the OnStar® system. Failure to reconfigure the system will result in an additional customer visit for repair.
